Access to Care, Race and Education Are Key Determinants of Erythropoietin Stimulating Agent (ESA) Use In Myelodysplastic Syndromes (MDS).

Abstract 3815

ESAs are recommended by the National Comprehensive Cancer Network for low-risk MDS patients with symptomatic anemia who have low serum erythropoietin (Epo) levels and limited transfusion burden. Because ESAs are costly and involve repeated physician office visits, socioeconomically vulnerable patients may be less likely to receive them. The advent of reporting MDS to the Surveillance Epidemiology and End Results (SEER) registries as a cancer beginning in 2001 affords the ability to examine population-based utilization of therapies for this group of disorders. Medicare patients diagnosed with MDS from 2001–2005 were identified in SEER registries. Medicare claims provided detailed treatment-related data on ESA use. Bivariate analyses and multivariate logistic regressions examined the effects of patient demographic, socioeconomic, geographic and health status characteristics, measured during 12 months prior to MDS diagnosis, on the probability of receiving ESAs between the year prior to SEER-reported diagnosis and either death or censoring. Analyses examined all MDS patients, and a subset with lower-risk MDS (modified French-American-British categories of refractory anemia (RA), RA with sideroblasts (RARS), refractory cytopenia with multilineage dysplasia (RCMD), or del(5q) syndrome). The MDS sample included 7,385 patients, with 2,568, or 35%, identified as lower-risk. 66% of MDS patients (70% of lower-risk) received ESAs at some point during the observation period. Multivariate estimates indicated that ESA use rates were higher among patients with an FAB classification of RARS relative to RA (Odds ratio [OR] 1.27; 95% Confidence interval [CI] 1.02–1.57), a history of transfusions prior to MDS diagnosis (OR 1.82; CI 1.58–2.09), diagnosis in 2004 versus 2001 (OR 1.21; CI 1.02–1.43), and residence in the South (OR 1.36; CI 1.12–1.65) or West (OR 1.28; CI 1.06–1.56) compared to the Northeast. Lower ESA use rates were also associated with baseline health status measures, including a diagnosis of dementia (OR 0.62; CI 0.51–0.76), other severe mental illness (OR 0.54; CI 0.36–0.83), use of a wheelchair (OR 0.71; CI 0.58–0.88) or nursing home stay (OR 0.40; CI 0.30–0.53), and demographic and socioeconomic characteristics including age 85+ compared to age 65–69 years (OR 0.76; CI 0.61–0.95), black versus white (OR 0.77; CI 0.62–0.97), prior-year enrollment in Medicaid or Medicare Savings Programs (MSP) (OR 0.63; CI 0.53–0.75), and area percent of adults without any college education (OR 0.99; CI 0.98–1.00, p<.001). Among the lower-risk patients, the effects of RARS category, prior period transfusions, dementia, wheelchair use or nursing home stay, prior period Medicaid, and region of the country were similar to those in the full cohort. Lower-risk males were less likely than females (OR 0.76; CI 0.61–0.94) to receive ESAs. Diagnosis year and race were not significant factors in lower-risk patients (OR 0.96; p=0.84 for blacks compared to whites). Access to care, as reflected by Medicaid/MSP enrollment, race, and low educational attainment are key determinants of ESA use. Patient mobility and cognitive ability are also associated with reduced use. These data suggest that the current health care system may induce disparities in access to potentially important palliative care for patients with MDS. Ongoing research is examining the relationship between physician characteristics and receipt of ESA. Strategies to improve access should be considered, including changes to Medicare coverage of ESAs that could facilitate home administration.